


Old Souls, New Tricks

by deathrite666



Category: Undertale (Video Game), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: F/M, Multi
Language: English
Status: In-Progress
Published: 2020-10-26
Updated: 2020-10-30
Packaged: 2021-03-09 05:14:39
Rating: Not Rated
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,027
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27208735
Author URL: https://archiveofourown.org/users/deathrite666/pseuds/deathrite666
Summary: Society is a lie. Before it was built based on the work and co-operation of people working together to better themselves and the lives they lived, improving the world as they go.The current one was built on who had the best quirks and ‘heroes’ that were in it for fame or glory and even in some cases just the money. There were barely any heroes that were in the business for the right cause.This is what one Izuku Midoriya had decided as he recovered from the aftermath of Endeavors fight. It was time for that to change.
Comments: 2
Kudos: 25





	1. Tibia honest, That was rough

**Author's Note:**

> Aight so imma be real for anyone that reads this, this is my first story iv'e actually done. I constantly have tried to post before but keep getting psyched out in the end by various things so im not expecting this to be good. i just hope that someone out there doesn't look at this and freak out over its existence. Hopefully future chapters be longer too but kinda wanna see how this goes first.

_ (The Void) _

Izuku opened his eyes, not knowing what caused him to wake up. He'd just fallen asleep after thinking about what he saw earlier in the day, the destruction and the lack of care for the surroundings that Endeavor showed as he fought the criminal Viper Sting in the center of Musutafu shopping centre. He was greeted by a ‘sky’ of pure black above him. Sitting up he discovered all around him the darkness just spread infinitely. Even the ground below him was seemingly made up of the darkness.

“So, you're finally here” A voice sounded out from behind Izuku. He spun around seeing a figure around his height behind him, the figure was wearing a hoodie with the hood up, shadows concealing their face from Izuku's view. “You kept me waiting for quite awhile, Tibia honest i kind of never thought you'd develop the trait you needed for me to meet you.”

“Wait, what do you mean. Where even are we?, Develop the trait, waiting to meet me. I've never heard of anything like that” Izuku was confused and a bit scared of the location he was in, as far as he knew he'd just gone to sleep and now some hooded figure was talking to him. “Alright kid, don’t worry i'll start explaining, you're currently still asleep back at home bundled up in your bed. Your mind on the other hand well that's harder to explain, see right now the place we are in is called the void. Its what exists between the worlds and its a place where no living thing should really be. Why your here because I summoned your mind here so we could finally have the talk we should have had years ago.”

He took a second to pause and gain his breath back then continued. ”My names Sans, Sans the skeleton and I've been waiting for a long time for my successor to be born.” He stopped and pulled his hood down allowing Izuku to see his skull and take in what he was saying. “I belong to, well belonged i should say, a race called monsters. We were sealed below a mountain after a great war with humans. After we lost we despaired and tried for years to finally escape from that place, i'm not gonna lie and say it was peaceful either. To break the barrier we needed a soul of each soul type to match the barrier's magic. You're smart, you can guess where we got the souls from. We succeeded in the end and finally made it out only for it to go wrong.”

“But I've never heard of you, it'd be all over the news if that had happened.” Izuku protested, he's been all over the internet because of his hero ‘studies’. “That'd be true if it was your universe, tell me have you ever heard of the multiverse theory.” Izuku was stunned hearing this and he fell backwards trying to understand what Sans was saying. People had been trying to prove the idea of multiple universes and realities for years with no success. “Y..yeah the multiverse theory was that different decisions cause splits in b..branches so if one person chooses to do one thing, a different universe version chooses to do something else.”

“Good, you can follow this conversation until the end, now I come from a universe called Undertale. We were the base universe for our multiverse. The way it was explained to me by Ink was we were the only universe to exist at one point in the multiverse. So the Deity called fate created a skeleton based off me called Ink, his job was designed to paint different universes based off his imagination that were different from the original and he did a good job at first, but he started to create too much, so Fate was forced to interfere and even up the balance. She took a version of me from a timeline that had managed to get their happy ending. He'd died in the universes previous timeline and because of injecting artificial Determination, the soul trait of red, he'd managed to help the next sans of his universe to succeed in stopping their genocide route. She then twisted him into her destroyer of universes Error.” Sans looked at Izuku and noticed his confused expression “I can see your confusion, what's it about.”

“You mentioned a trait when I first woke up and again then when talking about determination, also i'm confused by what you said about a genocide route.” Izuku mentioned wondering if by trait he meant a certain soul trait. “Ah so the common themes of the universes would be they went one of 3 ways, a neutral route where the frisk of that world would kill a couple monsters and leave others alive, a pacifist route route where they’d kill nothing and befriend all the monsters they came across or genocide where they kill everything. Now onto traits thats a different matter, Monster souls like mine are trait-less but we can use multiple types of magic because we never lost it, humans on the other hand lost their magic but as they did so there souls took on a closer connection to their traits.”

“The original soul traits that the original universe new about are as follows, Red - Soul of Determination, Cyan - Soul of Patience, Orange - Soul of Bravery, Blue - Soul of Integrity, Purple - Soul of Perseverance, Green - Soul of Kindness, Yellow - Soul of justice. There are others now, multiverse and all that,so new ones formed but my world only dealt with those seven. Now your soul has had kindness your full life you've never raised a hand against others except in defence of others and you've always tried to help even enemies, you've also had patience as you've dealt with mocking and jeering since you were 4, biding your time to prove them wrong as you made your life's goal rather then snapping back and trying to fight. But you've had a blind eye on heroes, you never saw the dark side of the job, the corrupt, unworthy you've always seen the heroes you like as people that embodied the role despite their flaws, and that stopped you developing justice as a soul trait until recently, can you tell me why?.”

Izuku took a moment to think back on why his viewpoint on heroes might have changed, all his life he's idolised heroes always following the news on them and even in the last few yews analysing and making notebooks on the various heroes that existed. In fact he was out earlier today making a new page on….Endeavor. The Endeavor fight how he disregarded the civilians caught in the fight not even caring about the injured ones. Actively ordering his sidekicks to ignore any wounded and to go on pursuit of Viper Sting. ”It was the Endeavor fight wasn't it.”

“Correct, seeing how he acted, knowing that he's number 2 on the rating boards and nothing will happen to him despite the callous disregard of life, you realised that some heroes are almost as bad as the villains they hunt. This developed the Justice trait when you decided you'd change this, make the world see heroes needed to truly embody their role. And in developing Justice your soul had access to my two traits Justice and Patience and if your wondering why i had soul traits as a monster, my brother and I were artificially made by our father gaster and as such despite having a regular monster soul, our traits were instead shown in our eyes when we accessed our magic.”

Sans took a moment to move and slowly walked around Izuku, his hand glowing, He removed what looks like a glowing cyan and yellow heart from Izuku. ”This is your soul, notice how one side is yellow and the other is cyan, this shows the two traits you have. Now if you remember i said you had 3 traits you had Kindness as well which is green. I think to show that your my reincarnation, your body did something similar to me and pap, my brother and your hair and eyes show that soul trait clearly. In fact it wouldn't surprise me if when you use your abilities in future you get the flame effect around the eyes like pap and i did, though yours is likely to be green.”

“Now back to my talk about the multiverse and why you were needed as my reincarnation to begin with. A war broke out that spanned multiple universes yet only had about 100 participants, essentially one sans lost his universe and in attempting to get it back started taking core ‘code’ parts of every universe. As he did this he slightly destabilised every universe and even in the end with everything restored after the war ended the balance was damaged enough that the multiverse started to collapse. We pleaded with fate and destiny to help and they did in a way we didn't expect” after saying this he clicked his fingers together and his eye lit up, flashing between yellow and cyan as he summoned a floating draconic skull, it flew into the air and started to gather a lot of blue energy in its mouth. “Don't worry this attack ain't gonna hit you just need it for the light.” The skull shot the beam in a line into the darkness where it hit an orb in the distance, this lit the whole area up revealing it was a large plain made of darkened metal and full of tubes, each containing a new skeleton in it.

“Now we're in a version of the void that exists in your soul, each person here is another version of me. Fate and destiny chose to reincarnate every boss monster and the two main humans from Undertale and every alternate into a new multiverse, according to them there are multiple universes out in this new multiverse but you and the other incarnates will only be able to access them when you get to learn the powers of those that can naturally jump universes. Now we need to discuss what's gonna happen when you wake up. See as you train more with the powers and unlock more of the aus abilities I'll slowly wake them up here, as such this place will change and odds are you'll be able to come here via your own abilities. We need to train you on how to handle the powers you'll get. Since eventually you'll access some people who can manipulate the ‘codes’ that make up a universe so you'll need to learn computer coding too. It’ll be a long few years but we’ll get you there. Now you need to sleep, you got a lot to do and not a lot of time to do it in.”


	2. Awakening

**Summary for the Chapter:**

> Getting first glimpse into Izukus appearance when using magic, slight access to his magic being achieved and the start of training. Also the introduction of the ever important question from the genocide run.

**Notes for the Chapter:**

> The amount of people that gave my first chapter was insane given its only a few days old. honestly wasn't expecting it and it gave me the courage to write a second one. I hope i can keep putting out content that ain't bad and as time goes on i expect my writing to get better. I hope the people out their reading this have a good day and stay safe during this pandemic.

_ (Dagobah Municipal Beach) _

“Right, this is gonna be a bit exhausting.” Sans’s voice rang out through Izukus head as he stood on the beach. He’d woken up early to be able to start training using his powers and given the time he had off from school due to the ‘Incident’, he figured he'd be able to start getting a handle on the basics of his abilities. He had roughly 4 years before the start of U.A and compared to the other applicants who’d had their powers for years he didn't want to fall behind. “So to access your magic i'm gonna need you to start learning to meditate, you need to learn what it feels like to draw your magic from your core. We’ll probably get you able to feel it today but don’t worry if it takes a little while to get used to the flow, It can be killer at first.”

“Now a lot of people want you to sit down and center out all distractions when learning to meditate but we don't have time for you to learn that, so i'm gonna teach you a quicker route to get in the zone. I want you to imagine your mind as a dark void, doesn’t matter if thoughts are about. In fact I encourage you to keep thinking while trying this, After you have that void I want you to imagine a flame and you need to slowly start to feed your thoughts to that flame, just let go of them.”

Izuku listened to what Sans was telling him, he stood staring out into the ocean and slowly closed his eyes. He took a deep breath and started to imagine the void from his conversation with Sans. he felt the sand beneath his feet, smelt the ocean air and slowly imagined a bonfire in the center of the void. He started to feed it his thoughts at first, slowly letting go of the ideas he had of how the training would go, letting go of his fears of failing, his anger at how katsumi acted towards him and others, his trepidation at being so far behind others, his feelings of worthlessness for being less in the eyes of society. Suddenly something seemed to click inside of him and he heard a roaring in his eyes.

“Thats it kid, well done. You managed to access your core, now while you still can why don't you go check out what you look like with conscious use of your magic.” Izuku opened his eyes and walked over to the water, he looked down and saw his reflection. His eyes were ablaze with what looked like fire. His left eye was glowing a green that was almost like gems, his right a two-tone mix of yellow and cyan. It was mesmerising how it was streaming towards the sides of his face, continuing its flow into his hair with what looked like emerald flames trailing across his curls. “What did you mean while i still could, Sans?” he asked. “ Well given your human and not really a monster despite reincarnating from me, you're not made of magic like I was so you should be collapsing of magic overuse in about 3 seconds.” After saying that Izuku felt drained and he collapsed like a puppet with his strings cut.

_ (4 Hours later) _

Izuku woke up feeling groggy, the last thing he remembered was seeing his eyes after unlocking his magic before everything cut out.”You're finally awake again it seems kid, good now you’ve unlocked your magic now you're never gonna have to do that again. You collapsed because the way i had you meditate brought your magic out straight away and you couldn't stop it. Usually you’d have done standard meditation for a few years to learn to access it bit by bit. Unfortunately if you want to be on this road you couldn't take the long route, the shortcut was needed. Fortunately though from tomorrow onwards i can start to teach you the basics to controlling it.” Izuku got up feeling incredibly stiff all over, and slowly made his way to his bag. He sat down and pulled out a notebook.”Hey Sans, do you mind explaining some of your powers just so i can make notes? I think i'm gonna make pages for the others too.” Sans thought for a second trying to decide if it was worth the explanations, and came to the conclusion it wouldn't hurt if the kid had some form of reference for the future, as keeping track of his powers was gonna be hard enough at first let alone when he starts developing the others.

“Alrighty kid, so the first is my bone attacks. Of course i use bones because it fits my motif but since it's magic formed into a specific shape you could make it anything, id advice that you stick to bones though as it's simple and something familiar to me for teaching you. Now these can be combined with various magic types but blue magic is the one you'll learn from me as it was my unique type. What it does is makes the bones harmless to those that stand still in them, any movement and they'll feel as real as the regular ones. Now this means you can disable enemies by beating them down and placing blue bones through them, as stated before unless they move it wont hurt them.”   
  


“Next is the other side of blue magic, you can use telekinesis while channelling blue magic around objects and souls. If you use it on a soul don’t worry you move the full body too, just the souls the best conduit to use the magic on. Teleporting is another ability I have but that’ll come in when you start learning coding, cus i take my ‘shortcuts’ by using my magic to say in the code I'm somewhere else and let the magic take me to the new zone. The gaster blasters require you to learn advanced bone magic first but they are essentially giant draconic skulls that gather my magic and fire it like a laser and then finally I'll teach you my most devastating power in a few years. You see, unlike a lot of other sans that existed, I only had 1 hp and 1 attack and defense so to counter that defensively I used my teleporting to dodge attacks, but I needed a way to deal damage despite being weak. I developed an attack that would attack the soul itself, a person's L.O.V.E or levels of violence for short is someone's way of measuring their capacity to hurt others. This is reflected in their soul so the higher the LV they had the more damage the karmic retribution would do to them. It works almost like poison in how it’d hurt others over time but it's unable to kill in general since it weakens the soul to near deathlike. 

Izuku kept track of this explanation and wrote 5 pages in the notebook, one for each power, each one with drawings of possible styles and theories on how to improve them. He stuttered on hearing one of the powers was poison based but carried on writing about it.”Sans you mentioned that you developed a magic that affected the soul directly, does this mean you could see souls.” Sans took a second and tried to explain the mechanics behind soul checking.”By sending your magic into someone's soul you can CHECK them, this allows you to see how strong they are in both attack and strength, as well as what their LV is. My world couldn't see others H.P but i know some of the other mes could so it's possible you can too.”

Izuku got up and walked towards the clear section of the beach.”Sans I don't want you to go easy on me with teaching me, i'm too behind others that have had their quirks for years. I have at most 4 years before I join U.A and I'll be against others that have had their powers for 14 years in most cases. I’m 13 now nearly 14, and I need to work harder to get in. Please, i don't care if i lose what social life i could possibly gain if it means i make my dreams happen.”

San’s response took awhile to come and it came in a much rougher voice than the previous conversations. ”If you truly want that, understand I will  P U T Y O U T H R O U G H H E L L.  You're going to hate almost all of what you'll do but it will be the fastest way for you to learn.” He let out a sigh and asked Izuku a question. ”Listen kid, if I'm gonna train you like this I have to ask you a question, I need to know the answer before I can justify fully committing to teaching you my tricks. Now this is a question my brother once asked me and it's something I've always kept in mind due to my role as the judge. I have to view every possible response to a situation and must choose the best outcome I can. Anyway the question is, Do you think even the worst person can change if they just try.”

Izuku thought for a second, ideas on how to respond to Sans' question turning over in his mind.” I feel like I could answer this a few ways but I think the best response I could give to this is, yes people can try to change but only if they are given the chance and opportunity too. Some people may want to change but don't have the means too and some may have the means but may have been in a situation for so long they can’t try to change without help. I feel like as someone with power it should be my responsibility to help those that need it.”

Sans thought about the answer for a second and started to chuckle. His chuckles subsided after a few moments and he spoke to Izuku in a mirthful yet serious tone. “In all my years and across several universes I've heard and even asked that question several times, yet I've never heard an answer like that. It’s a good one don’t get me wrong there but is the first time I've ever heard it even the star sanses never gave me that sort of answer. Alright kid i’ll put my best effort to train you tibia honest though it’ll be a new experience for more i'm usually too bone tired to put much effort into things and yes the puns are a thing you'll probably pick up from us, we all make them even the ‘bad’ ones.”

_ (Next day) _

“So we need to explain these powers as a quirk to be able to be a hero. What do we call them so that the paperwork is correct.” Izuku asked Sans as he walked to the local branch of the QRO, the quirk registration offices held paperwork on all of the registered quirks the public had. They only did the basic’s allowing hero schools to handle more in depth records but it was enough that it was required by the public to register after their quirk manifested. ”Well you are insanely powerful or you will be, just name your quirk karmic retribution because someone's karma has to be really bad to end up fighting you. If they need an explanation to it just explain a couple of your abilities, even if you can't use them yet just say a couple appeared on your awakening. From what you said late quirk awakenings are almost always powerful.”

He had thought about registering his quirk now to avoid trouble down the line when U.A couldn't find anything out about his abilities. If he was still going to become a hero, underground or on the main board, he’d need to be above board about things like developing a quirk at 14. Just because he can't tell them his powers were magic he gained from a talking skeleton from a different universe without sounding insane doesn't mean he needed to be quiet about the abilities to begin with. All the training he'd done in just this week alone was tiring and hellish, he’d learned how to form bones in the air and in the ground ready to burst out. They came slowly now but Sans had assured him as he practised more he’d speed up how fast he formed them, he'd also started on the use of telekinesis via blue magic. He was using it to clear some of the trash on the beach trying to make the place better.

Once he registers he was heading back to the beach he was promised by Sans he'd learn how to manipulate multiple objects at once using his magic and he wanted to get to finished before the end of the week, he had work that needed to be finished for school and with how hard he was being trained he didn't have a lot of spare time to do it in.

**Author's Note:**

> Any end notes will obvs go here in future chapters, comments are accepted as without feedback, how am i meant to get any better.


End file.
